CA2588916A1 - Method for operating a well jet device in the conditions of a formation hydraulic fracturing - Google Patents

Abstract

The inventive device operating method consists in running a jet pump into a well, in releasing a packer above a productive formation, in pumping a hydraulic fracturing fluid into the formation though a blocking insert in the pump channel, in extracting said blocking insert, in running a flexible pipe into the well through a sealing unit and in arranging the lower end thereof at a level of a lower formation perforation interval. When the formation is drained, the method consists in supplying a fluid for washing a bottomhole by means of the flexible pipe and maintaining the ratio between the pressure value in said flexible pipe and the working medium pressure in a casing annulus within a range of equal to or greater than 0.98. When at least two volumes of hydraulic fracturing fluid pumped into the formation is pumped out, the fluid supply in the flexible pipe is stopped. After than and not early than in 5 minutes, the inventive method consists in shutting off the working medium supply to the pump nozzle, in examining the formation for evaluating the productivity thereof and in bringing the well into operation. Said invention makes it possible to intensify well examining, testing and preparing works and to increase the reliability of data on the well operating readiness.

Claims

A method for operating a well jet device consisting in that a jet pump with a stepped through passage made in the body thereof and a packer with a through passage and a stem with an inlet funnel, which are arranged below the said jet pump, are lowered on a flow string into a well; then the packer is released after arranging it above a productive formation; then a blocking insert with a central through passage is arranged into the said stepped through passage, and a hydraulic fracturing fluid or a mixture of a hydraulic fracturing fluid with chemical agents is pumped into the said productive formation; then the said blocking insert is extracted to the surface, and a flexible tube passed through a sealing unit with the possibility of being moved relative to the latter is lowered into the well through the flow string; the lower end of the flexible tube is arranged below or at the same level with the lower perforation interval of the productive formation, during the process of lowering the said sealing unit being arranged in the said through passage of the jet pump; a liquid working medium is delivered to the jet pump nozzle over the well annulus; and the productive formation is drained by creating differential pressure drawdown in the under-packer area of the well, a fluid for washing the well bottom being delivered to the well by the flexible tube at the same time with or after creating stable differential pressure drawdown on the productive formation, the relation between a pressure P f in the flexible tube and a pressure P w of the said liquid working medium being maintained within the range (P f: P w) <= 0.98; after pumping out a fluid of the productive formation or a mixture of the hydraulic fracturing fluid and chemical agents in a quantity equal to at least twice the quantity of the hydraulic fracturing fluid pumped into the productive formation the supply of the fluid for washing the well bottom is stopped, and thereafter, but not earlier than in 5 minutes, the supply of the liquid working medium into the jet pump nozzle is stopped also;
afterwards the flexible tube together with the sealing unit is extracted from the well, and hydrodynamic and geophysical studies of the productive formation are carried out with the use of a jet pump in order to evaluate the productivity of the formation; and then works are carried out on putting the well into operation.